Technical Field
The present disclosure relates to compounds capable of modulating the mu-opioid receptor (“MOR”), the delta-opioid receptor (“DOR”), and/or the kappa-opioid receptor (“KOR”), and methods of using these receptor modulators for the treatment of pain.
Description of Related Technology
Opioid receptors are G protein-coupled receptors found in the brain, spinal cord, and digestive tract that have a wide variety of biological function, including controlling pain sensation. There are three recognized “classical” opioid receptor subtypes: mu-opioid receptors (MOR), delta-opioid receptors (DOR), and kappa-opioid receptors (KOR). The natural ligands for opioid receptors include enkephalins, endorphins, endomorphins, and dynorphins, and an abundance of non-peptide or synthetic ligands have been discovered or developed to modulate opioid receptor activity.
Opioid drugs, including morphine, are the primary treatment for severe pain, e.g., post-operative and chronic pain conditions. Unfortunately, the use of opioids can lead to the development of a number of undesirable side effects, such as nausea, pruritis, sedation, mood swings, respiratory depression, constipation, and perhaps most problematically, dependence/addiction and tolerance. (Benyamin, R. et al. Pain Physician 2008; 11:S105-S120).
Despite a considerable amount of research into opioid-based therapeutics, there remains a need for analgesics that exhibit little or none of the adverse effects associated with traditional opioid use.